3,197 research outputs found

    In the Name of Liberty: An Argument for Universal Unionization

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    For years now, unionization has been under vigorous attack. Membership has been steadily declining, and with it union bargaining power. As a result, unions may soon lose their ability to protect workers from economic and personal abuse, as well as their significance as a political force. In the Name of Liberty responds to this worrying state of affairs by presenting a new argument for unionization, one that derives an argument for universal unionization in both the private and public sector from concepts of liberty that we already accept. In short, In the Name of Liberty reclaims the argument for liberty from the political right, and shows how liberty not only requires the unionization of every workplace as a matter of background justice, but also supports a wide variety of other progressive policies

    Firm-level adjustment costs and aggregate investment dynamics – Estimation on Hungarian data

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    This paper uses Hungarian data to estimate the structural parameters of a firm-level investment model with a rich structure of adjustment costs, and analyzes whether non-convex adjustment costs have any effect on the aggregate investment dynamics. The main question addressed is whether aggregate profitability shocks (as a result of monetary policy, for example) lead to different aggregate investment dynamics under non-convex and convex adjustment costs. The main finding is that while non-convex adjustment costs make investment lumpier at the firmlevel, they lead to a more flexible adjustment pattern at the aggregate level. This is because the model is calibrated to have the same proportion of inactive (i.e. non-investing) firms under convex and non-convex adjustment costs, but the average size of new investment of active firms is higher under non-convex adjustment costs.Capital adjustment costs, lumpy investment, irreversible investment, aggregation

    Modelling legacy telecommunications switching systems for interaction analysis

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    Magnetospheric and auroral processes

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    Progress was made on the following two projects within the semiannual period: (1) simulations of the magnetic storm of April 1988 using the Magnetospheric Specification Model; and (2) improvement of a user-oriented electric-field model

    Particle precipitaion into the thermosphere (invited review)

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    A review of research on particle precipitation into the thermosphere is presented. Particle precipitation plays an important role in thermospheric dynamics, often being both the most important ionization source and the most important heat source, comparable to Joule heating rates in the auroral zones and typically exceeding solar ultraviolet as an ionization mechanism in the nightside auroral zones and winter polar caps. Rees (1963) has shown that, roughly speaking, one electron-ion pair is produced by each 35 eV of incident electron energy flux; thus, over half of the incident electron energy flux goes into heating rather than into ionization. Precipitating ions also can produce ionization, also requiring roughly 35 eV per pair; however, since ion energy fluxes are typically much weaker than electron fluxes, they have often been neglected. The particle precipitation into the thermosphere is both an important ionization source and an important heat source; since the globally integrated value can vary over more than a factor of ten, and the instantaneous local rate can vary over nearly three orders of magnitude global, maps of precipitation rates are extremely important for predicting thermospheric weather

    Dynamics explorer data analysis

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    The project has shown unambiguously that auroral acceleration is caused by electric fields aligned parallel to the Earth's magnetic field. Evidence was shown of significant ion heating as ions are accelerated upwards in auroral electric fields. This heating is most likely caused by the two-stream instability. The fate of upward ion beams associated with auroral arcs is shown; they appear in the opposite hemisphere as dispersive ion precipitation events. Magnetic merging of the Interplanetary Magnetic Field occurs with both closed dayside magnetospheric field lines and open tail lobe field lines simultaneously nearly 30 percent of the time. The sunward flow in the dawnside plasma sheet is 20 percent smaller, on average, than in the duskside. The convection throat is displaced slightly more toward dawn for B sub y greater than 0 than for B sub y less than 0

    Dependence of Domain Wall Structure for Low Field Injection into Magnetic Nanowires

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    Micromagnetic simulation is used to model the injection of a domain wall into a magnetic nanowire with field strengths less than the so-called Walker field. This ensures fast, reliable motion of the wall. When the wire is located at the edge of a small injecting disk, a bias field used to control the orientation of the domain wall can reduce the pinning potential of the structure. The low field injection is explained by a simple model, which relies on the topological nature of a domain wall. The technique can quickly inject multiple domain walls with a known magnetic structure

    Enhancing Domain Wall Speed in Nanowires with Transverse Magnetic Fields

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    Dynamic micromagnetic simulation studies have been completed to observe the motion of a domain wall in a magnetic nanowire in an effort to increase the field-driven domain wall speed. Previous studies have shown that the wire dimensions place a cap on the maximum speed attainable by a domain wall when driven by a magnetic field placed along the direction of the nanowire. Here we present data showing a significant increase in the maximum speed of a domain wall due to the addition of a magnetic field placed perpendicular to the longitudinal driving field. The results are expressed in terms of the relative alignment of the transverse field direction with respect to the direction of the magnetic moments within the domain wall. In particular, when the transverse field is parallel to the magnetic moments within the domain wall, the velocity of the wall varies linearly with the strength of the transverse field increasing by up to 20%. Further examination of the domain wall structure shows that the length of the domain wall also depends linearly on the strength of the transverse field. We present a simple model to correlate the effects

    Fast domain wall motion in nanostripes with out-of-plane fields

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    Controlling domain wall motion is important due to the impact on the viability of proposed nanowire devices. One hurdle is slow domain wall speed when driven by fields greater than the Walker field, due to nucleation of vortices in the wall. We present simulation results detailing the dynamics of these vortices; including the nucleation and subsequent fast ejection of the vortex core leading to fast domain wall speeds. The ejection is due to the reversal of the core moments by an out-of-plane field. The technique can be used to produce domain walls of known orientation independent of the initial state.Comment: 12 pages (3 figures

    Enhancing Domain Wall Speed in Nanowires with Transverse Magnetic Fields

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    Dynamic micromagnetic simulation studies have been completed to observe the motion of a domain wall in a magnetic nanowire in an effort to increase the field-driven domain wall speed. Previous studies have shown that the wire dimensions place a cap on the maximum speed attainable by a domain wall when driven by a magnetic field placed along the direction of the nanowire. Here we present data showing a significant increase in the maximum speed of a domain wall due to the addition of a magnetic field placed perpendicular to the longitudinal driving field. The results are expressed in terms of the relative alignment of the transverse field direction with respect to the direction of the magnetic moments within the domain wall. In particular, when the transverse field is parallel to the magnetic moments within the domain wall, the velocity of the wall varies linearly with the strength of the transverse field increasing by up to 20%. Further examination of the domain wall structure shows that the length of the domain wall also depends linearly on the strength of the transverse field. We present a simple model to correlate the effects.Comment: 11 pages, accepted by J. Appl. Phy
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